A mailing list is a list of email addresses which get the very same message simultaneously. When you send an e-mail message to the mailing list address, it will be redirected to all the addresses on that mailing list automatically, but none of the receivers will learn who the other recipients are. Generally, users have to subscribe to a mailing list, but occasionally email addresses are included manually without their owners’ approval. Depending on the given list management software, you may also be able to add new subscribers, so users cannot subscribe to a mailing list unless you authorize their signup request. The mailing list option is rather valuable if you want to send regular newsletters or some other sort of regular announcements to customers, since you’ll need to send only one single e-mail and all the subscribers will get it immediately. As a result, you won’t need to insert a huge number of email addresses manually.